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What kind of things? Methods? Types of questions? How to find testers? What questions to ask? Please be more specific.
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Rahul♦Sep 21 '10 at 7:42

Hi. Are you talking about usability testing (finding problems by getting real users to interact with the UI), automated UI testing (using tools like Selenium or Window Licker to write programs to see whether the UI does what it should do), or some kind of exploratory testing (when you sit and interact with the system and try and find problems.)?
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adrianhSep 21 '10 at 13:16

I was thinking more along the lines of things to look for to evaluate UI implementations. For example, rules of thumb for what types of controls to use in what kinds of situations.
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Ron PihlgrenSep 24 '10 at 4:47

8 Answers
8

Jakob Nielsen has a good overview of some concepts to consider when testing an interface. Without more specifics in your question though, this is about as well as I can help.

These are ten general principles for
user interface design. They are called
"heuristics" because they are more in
the nature of rules of thumb than
specific usability guidelines.specific usability guidelines.1

Apple still have 'Human Interface Guidelines' on their website - but they've reduced the amount of generic content (particularly the pschology background) - and made them more biased towards 'how to design the Apple' interface: